Timber carrying vessel



t Unlted States Patent 1111 3,540,399

[72] Inventor Karl Olol Gunner Gabrlelsson [56] References Cited 1 A l N I7);;n;jso3vagen 76, Domsjoverken, Sweden UNITED STATES PATENTS [2 1 P 1,788,138 1/1931 Wilband m1... 114/27 [22] F1led Feb. 6, 1969 [45] Patented 17,1970 3,356,058 12/1967 Lunde 114/27 [32] Priority Feb.-7, 1968 Primary Examiner-Trygve M. Blix [33] Sweden Attorney-lanes and Chapman [31] 1579/68 [54] TIMBER CARRYING VESSEL 11 Claims, 8 Drawing Figs.

[52] US. Cl. 114/27, ABSTRACT: A timber carrying vessel has buoyancy tanks at 1 1 14/72 the forward and aft ends thereof so that the top end of the hold [51] Int. Cl B63b 35/30 Can either be disposed above or below the surface of the [50] Fleld of Search 114/27, 26, water. Arms are pivotally mounted on the sides of the hold 72, 73 and keep the cargo in place within the hold.

' Patented Nov. 17, 1970 Sheet Patented Nov. 17, 1970 Sheet Patented Nov. 17, 1970 3,540,399

Sheet 3 014 Patented Nov. 17, 1970 3,540,399

Sheet 4 014 TIMBER CARRYING VESSEL The present invention is concerned with a water-going vessel, for transporting bundles of elongated objects which have a lower specific gravity than water, such as round wood, e.g. pulp wood, saw timber, which can be loaded and off-loaded considerably faster than has hitherto been the case.

One serious problem encountered by shipping companies is the long periods of quayside inactivity of the ship during the loading or discharging of its cargo.

Since one of the basic economic facts of transportation is that the ship is earning revenue only when carrying cargo, and since the costs entailed by the ship during the inactive period of the vessel at the quayside must be settled from the aforementioned revenue, a shortening of the time taken to load or discharge the cargo would greatly contribute towards an increase in profit. This factor has been the cause of exhaustive activities in rationalizing the work at the docks and improving loading and off-loading equipment. Efforts have primarily been concerned with making this equipment more effective. Thus, for instance, ships winches have been replaced to a great extent with appropriate deck cranes and hoists or traverses which run on rails, while the efficiency, operational capacity and range of action of the shoreside apparatus and equipment have been increased. Although the efficiency etc. of this equipment has been increased quite considerably, the time taken to load and unload a ship is still so long-even in the most favourable cases-that further shortening thereof would result in a substantial profit increase. Furthermore, in certain areas the extent oftechnical development by no means corresponds to the requirement of increased efficiency. This is particularly true of the transportation of wood by sea, which is carried out under relatively uneconomical conditions. For instance, towing of log rafts or floats is still the most common method of transporting timber to the pulp and sawmills. This method involves collecting and lashing the logs in large bundles, connecting the bundles to form a long raft and towing the raft to the unloading station at a speed of from 1.5 to 2 knots. One great disadvantage with this form of transport is that it can only be effected under favourable weather conditions, which means that it is often necessary to leave the correct route and seek shelter off the coast in the event of worsening weather conditions. Consequently, the towing vessel is not utilized to the best advantage and the costs per quantity of wood transported increase in relation to the extra distance travelled as a result of the deviation from the correct route. Thus, it is estimated that a timber-carrying tug in normal cases can only utilize about percent of the time at disposal during the towing season. The low speed at which the rafts are towed also constitutes a disadvantage, among other things from the point of view ofmaneuvering the raft. In the case of transporting roundwood by sea over long distances, the entire load is usually stored on board ship. In recent time, several different methods have been suggested for shortening the time taken to load and discharge the cargo. For instance, a vessel has been suggested which lacks holds in the true sense of the word, and instead presents a hull which is divided into buoyancy tanks and upon which the whole timber load is placed. This vessel is loaded in a conventional manner, by means of lifting devices, and discharged by causing the vessel to list, through the medium of the tanks, to such an extent that the whole load slides overboard. The off-loading method is effected relatively faster than previous methods, but presents the serious disadvantage that the high load on deck causes the ship to be unstable and less capable in heavy seas. The risk oflosing part of the load in high seas is also great. Another disadvantage with a vessel of this construction, is that the hull must be heavily reinforced, to be able to withstand the heavy strains encountered when the load is discharged. This greatly increases the cost of building the vessel as well as its weight; this latter factor involving a corresponding decrease in the load-carrying capacity of the vessel. It has also been suggested that timber could be loaded and discharged onto and from ships by floating the timber into and out of the holds, through openings or gates disposed in the stern of the vessel. This means that the vessel must have one,

single hold, free from bulkheads. and that the hull must be fitted with buoyancy tanks of such size that they are able to support the vessel even when the hold is full of water. When the vessel is propelled by its own machinery, the machinery consists of two separate units, each connected to a propeller and installed in a special machine room, in the stern portion of the vessel. The machine rooms are thus remote from the space through which the timber is floated into and out of the vessel. When loading, the gates are opened and the vessel settled deeper into the water by filling the tanks with water, so that single layers of timber can be floated into the hold without touching its bottom. When the hold has been loaded with a single layer of logs the ship is lifted slightly by emptying water from the tanks, so that the logs rest on the bottom of the hold, where they are lashed fast with chains or the like. The vessel is then sunk again so that another layer of logs can be floated into the hull and chained to the hull on top of the first layer. When the hold has been filled to the desired level the stern gates are closed. The advantage to be gained with this method is that loading can be effected without cranes, winches etc. However, because it is constantly necessary to trim the buoyancy tanks whilst loading the vessel and because the task of floating each individual layer of logs into the hold is time consuming and, above all, in view of the fact that each layer of logs must be chained fast to the hold no great saving of time is obtained in comparison with conventional loading methods. A great disadvantage with vessels of this type is that said vessels cannot be fitted with bulkheads, since these would impede the passage of the logs through the stern, and the vessel has to be strengthened in some other manner. The necessary division of the machine room constitutes another disadvantage with vessels of this type. The load is unloaded in a manner analogous to the loading operation, the depth of the vessel in the water being trimmed by means of the tanks so that, subsequent to releasing the chains, the layers of logs can be floated in sequence out through the stern of the vessel.

The present invention eliminates the aforementioned disadvantages, and enables timber to be loaded onto and discharged from water-going vessels much more rapidly than has hitherto been the case. The invention is concerned with a timber carrying vessel provided with a forecastle and a poop and of twin or single hull construction fitted with buoyancy tanks at the forward or after portions thereof, for transporting whole bundles of timber or timber frames, and is mainly characterized by the combination of an open top hold which extends from the forecastle to the stern of the vessel and adapted to store the load in a fully or partially floating condition during transport, and means for communicating connection with the sea, means for raising and lowering the vessel so that the top edge of the hold lies above or below the level of the surface of the water, and means which are rotatably mounted about shafts in the cross direction of the vessel and mounted on one or both of the upper edges ofthe hold extending in the long direction of the vessel and which are intended to retain and force the load into hold and stabilize the vessel during transport, and means connected to the retaining means to rotate said means about the shafts, said rotary movement being restricted essentially solely by the sides ofthe hull.

The invention will now be described with reference to an embodiment thereof and to the accompanying drawings, in which:

FIG. 1 is a horizontal view of a sea-going vessel;

FIG. 2 is a horizontal view of the vessel;

FIG. 3 is a perspective view of load retaining means;

FIGS. 46 show different loading stages;

FIG. 7 is a cross section through the center of the vessel during one stage of the unloading procedure; and

FIG. 8 shows another embodiment of the load retaining means.

In FIGS. 1 and 2 the reference numeral 1 indicates the hull, which comprises a forecastle with a head 2 and a poop with an afterpart 3 which houses the propelling and auxiliary machinery, and four open top holds 4a-4a' which extends sequentially lengthwise of the vessel from head to stern. In the embodiment according to the invention, the holds are separated from each other and from the forecastle and stern of the vessel by bulkheads 5a5e. However, it is not necessary to separate the holds since they can just as well be combined to form one single hold, in which eventuality the hull is strengthened differently. It is also possible to divide the hold in the manner indicated, by means of bulkheads and join said bulkheads together by means of bulkheads extending longitudinally in the center plane of the vessel. This construction imparts considerable rigidity to the hull. A space 6 is arranged in a con ventional manner stern of the vessel, to serve as crew accommodation, and a bridge 7 from which the vessel is controlled. The hull 1 is fitted with twin sides and bottoms, and has decks over the forecastle and stern of the vessel. The hold has no upper deck. The space between the twin bottoms and sides is divided into a number of watertight tanks 8 (see FIG. 7) which can be made to communicate with the sea via a system of pipes and pumps in the machine room. Arranged on the upper ones of the side tanks of the vessel on either side of respective holds are a number of identical retaining means 9. Each means consists of an arm 10 of framework structure (FIG. 3) and is securely attached at one end with a shaft 12 rotatable in a bearing 11. The arm 10 may, of course, be of shell construction or any other suitable construction. The bearing 11 is fixed at the upper edge of the external sides of the hull so that the shaft extends generally parallel with said edge, the arm thus being rotatable in the cross direction of the ship, and so that the distance in the longitudinal direction of the ship between two adjacent retaining means is substantially the same on both sides of the hull. The arm 10 extends from its pivot point so that its free end is located somewhat on the opposite side of the fore-andaft line of the vessel when the arm is swung in to the horizontal position. Fixed on each arm 10 is a coupling means 14, by which two opposing arms on opposite sides of the hold can be connected together over the hold. Each retaining means is provided with a hydraulic motor 15, which is connected to the shaft for its rotation. The hydraulic motors can be operated from a central position in the vessel, e.g. the bridge. Of course, these drive means need not be hydraulic and the retaining means can be operated mechanically or in some other suitable manner, similarly the motors may be adapted so that two or more retaining means are operated by the same motor (FIG. 3 shows this embodiment).

The vessel is loaded in the following manner. Before the vessel arrives at the loading station, the lashed bundles in the water are towed to mooring dolphins. The bundles shall be turned so that their long sides face the dolphins and together cover a regular surface on the water, the length of which along the dolphins being slightly less than the length of the hold in the vessel and the extension of which from the dolphins corresponding generally to twice the width of the hold. The distance between the dolphins should be such that the retaining means of the vessel can be inserted unhindered therebetween when mooring the vessel. When the vessel has arrived at the loading station the retaining means are positioned by means of the hydraulic motors, so that the arms 10 on one side ofthe vessel extend upwards while the arms on the opposite side extend down into the sea. The vessel is moored to the dolphins on the outside of the timber float and with the side on which the arms depend into the sea facing the logs. The connections between sea and the hold and the tanks surrounding the hold are then opened to allow water to flow therein to increase the draught of the vessel. These connections are assumed to be so dimensioned that filling is effected rapidly. It is, of course, also possible to take on water by means of the vessels own pumps. Filling is continued until the tanks are partially filled and the holds completely filled with water. The vessel is held afloat in its new position of equilibrium in the water by the buoyancy of the forecastle and stern of the vessel and the partially filled tanks. This buoyancy is assumed to be such that, in the new attitude of the vessel, the hold openings are located at a distance below the surface of the water which exceeds the draught of the float of logs adjacent thereto (FIG. 4). The vessel is now pulled sideways by means of the mooring lines and capstans or winches in under the float of logs until the upwardly extending retaining arms contact the float. Whilst maintaining the tension in the mooring lines, the upwardly extending arms are rotated outwardly from the vessel, so that said vessel can be drawn further in under the float of logs. When the vessel is positioned approximately beneath the center of the float, movement of the arms is ceased and the capstans stopped, whereafter the arms are locked in the position thus obtained. The downwardly extending arms, beneath the float of logs are then rotated into contact with the float (FIG. 5). It should be ensured during these operations that the longitudinal position of the vessel in relation to the dolphins is such that said dolphins do not obstruct the movement of the arms. If necessary, the position of the ship can be adjusted by means ofits own propelling machinery or the capstans. The lines mooring the float of logs to the dolphins are released when the vessel has been positioned with the hold situated beneath the float and the float held by the retaining means. The arms are then rotated towards each other, to clamp the float of logs in its cross direction and force said float into the holds. The arms continue to be rotated until they are directed generally vertically upwards, whereafter the tanks are emptied of water. This vessel is, in this way, lifted in the water to a position in which finally the openings to the holds are located somewhat above the surface of the water (FIG. 6). The retaining arms are then further rotated towards each other, to force the load held therebetween downwards. Since the holds are still in open communication with the sea the vessel is, in this way, via the arms and the wood floating in the holds, lifted further out of the water and is supported by said wood to an extent which is determined by the buoyancy of the wood. Subsequent to the arms being rotated to a sub stantially horizontal position, the ends of opposing arms are joined together by coupling means 15. It is also possible to first lock the arms in a position in which they extend upwards or outwards, to facilitate the task of the arms in forcing the float of wood down into the hold. The tanks are then emptied and the vessellifts in relation to the surface of the water, whereupon the load and the bundles of wood slide down under their own weight, along the inclined arms and down into the holds. When the arms are then rotated towards each other the majority of the load is already within the standing rigging of the vessel. If desired, the vessel can be lifted still further out of the water by draining the tanks and holds.

Unloading is effected in substantially reverse order to loading. When the vessel arrives at the unloading station it is anchored where the wood is to be off-loaded, whereupon the tanks are partially filled with water, to cause the vessel to sink to a position in which the openings to the holds are located slightly beneath the surface of the water. All retaining arms are then rotated upwards. While rotating the arms (FIG. 7) the pressure of said arms against the load ceases progressively, whereby the load lifts in relation to the surface of the water and the ship sinks to a corresponding degree. When the distance between opposing arms is sufficiently great they lose contact with the bundles of wood, allowing the wood to float unhindered to the surface. Rotation of the arms is continued until they are directed generally horizontally outwards from the side of the vessel, all bundles floating to the surface of the water. The vessel can then be swung about its anchorage, so that the bundles of wood can more easily float away. When the vessel is free of the bundles of wood, the buoyancy tanks are emptied, to lift the hold openings above the surface of the water, and the holds are drained. To prevent the bundles of wood from obtaining too high speeds when floating up from the holds, and causing damage to the arms as a result of im' pacts, it may be expedient to open the retaining arms and release the load before filling the tanks.

The greatest advantage to be gained with a vessel constructed according to the present invention is, as previously mentioned, the very short loading and off-loading times. A

vessel according to the invention can be loaded in roughly two hours, irrespective of its size. A further advantage of the vessel according to the invention is that no devices in addition to those aforedescribed are needed to take the load onboard, and neither does it require personnel to stow the load in the holds. Neither does loading of the vessel require the use of shoreside equipment, or the use of towing assistance over and above that which is normal when maneuvering a ship in harbor. Neither are the aforementioned dolphins used to moor the float of timber and the vessel absolutely necessary since the chainbouno float of timber can be anchored at any point where the depth of water permits the vessel to sink to loading position, with the hold openings submersed beneath the surface of the water. In this instance, the vessel is tied up at the anchored float and then sunk to loading position, whereafter the float of wood is drawn in over the vessel by means of capstans or the like, against the upstanding retaining arms on the opposite side of the vessel. Loading then continues as described in the aforegoing example.

Discharging of the cargo of the vessel according to the invention is also effected very rapidly, without requiring any personnel or equipment other than that carried by the vessel itself. Thespeed at which the bundles of wood rise to the surface from the holds can be regulated by the speed at which the retaining arms are rotated and/or the speed at which the ship is lowered in the water, thereby avoiding damage to the load despite the very short off-loading time. Because the vessel is partially supported during its voyage by the buoyancy of the load, the hull can be made much simpler than would otherwise be the case. This in itself is a great advantage, since the profitability of a vessel is greatly determined by the amount it cost to build. Since the vessel can be used in icebound seas, as opposed to towing vessels, which cannot be used under such conditions, the vessel according to the invention can also be used for longer periods of the year than vessels adapted to tow the wood. Furthermore, the period over which the vessel can be used can be further extended by fitting an icebreaking stem to the bows thereof. The following advantages are also gained with the vessel of the invention when compared with the transportation of wood by towing vessels. The costs entailed by arranging the bundles for towing disappear completely and the chain costs are considerably reduced. The total transportation costs at sea are only about half the corresponding costs entailed when towing in the conventional manner.

It should be understood that although the invention has been described and illustrated with reference to one embodiment thereof a plurality of modifications are possible within the scope of the spirit of the invention. For instance, in another embodiment of the invention the length of the retaining means is such that swung horizontally inwards said means extend across the hold to the opposite side thereof, where they can be secured by some suitable securing means. This embodiment offers the advantage whereby the arms can engage about a larger load, i.e. a wider timber float, than in the aforedescribed example. This means in principle that the timber float 'which can be taken on board in the hold ofa vessel according to this embodiment covers a regular surface on the water of a length slightly less than the length of the vessels hold and of a width approximately three times the width of said hold. Thus, when the timber is taken on board it will fill the hold in three layers, in superimposed relationship. Of course, the vessel can also be loaded in the normal way, by hoisting the load on board with cranes or the like, similarly as it is also possible to store a so-called deck load ontop of the retaining arms and the load held in the holds. For this purpose, the vessel can be fitted with support means which, similarly to the load retaining means for the holds, can be made to pivot about the shafts l2 and connected to corresponding rotation means. The support means may either be fixedly attached to the load retaining means for the hold or arranged for rotation independently thereof. In the former instance the joined supports and retaining means form substantially right angles to one another. FIG. 8 shows this embodiment. In the latter instance each retaining means and support means is provided with a coupling means, which enables them to be connected to and disconnected from the rotation means. When the support means are fixed to the retaining means they serve in upright position as a support for the deck load. This eliminates the time consuming task of manually erecting these supports. The deck load is taken on board in a conventional manner, by cranes etc. If the supports and retaining means are capable of pivoting independently of a each other loading and off-loading of the deck cargo is effected in essentially the same manner as that described above with regard to loading the holds. Of course, the deck load is not forced down vertically, but that the support means are locked in an upright position on either side of the deck load. To assist the wood in sliding into the hold, down the retaining arms, said arms can be connected in pairs by means ofa plate, for instance, which covers the space between the arms so that the wood slides against the plate instead of the arms. This presumes, of course, that the pairs of arms thus joined are operated by the same rotation means.

Furthermore, it is also possible in accordance with the invention to use a single hull construction instead of a double hull construction, provided that the forecastle and stem of the vessel are fitted with suitable buoyancy tanks. The advantage to be gained hereby, is that a greater portion ofthe hull can be used as storage space than in the case of a twin hull structure. On the other hand, the twin hull construction does not require as strong stiffening members, in the form of bulkheads etc.

Obviously, the vessel of the invention need not be selfpropelling, but can, if so desired, also be a towed vessel.

Furthermore, if desired the retaining means may be mounted along only one side of the vessel, although in this instance the load capacity of the vessel is reduced somewhat in relation to the possible capacity ofa vessel in which the means are mounted on both sides thereof.

lclaim:

l. A timber carrying vessel of the type presenting a forecasv tle and a poop and being of twin or single hull construction and having buoyancy tanks at the forward and after sections thereof, intended for transporting loads of timber, characterized by the combination of an open top hold which extends from the forecastle to the stern of the vessel and is adapted to store the load in a fully or partially floating condition during transport, and means which can be placed in communication with the sea, means for raising and lowering the vessel in relation to the surface of the water to situate the top edge of the hold above or beneath said surface, and means which are rotatably mounted about shafts in the cross direction of the vessel on at least one of the long edges of the hold and which are intended to retain and bring pressure to bear on the load in the hold and stabilizing the vessel during transport, and means connected to the retaining means to rotate said retaining means about the shafts, the rotary movement being restricted essentially solely by the sides of the hull.

2. The vessel of claim 1, characterized in that the rotation means are hydraulic motors.

line of the vessel and the opposite side of the hold, so that opposing retaining means overlap and lie in contiguous, adjacent relationship.

5. The vessel of claim 3, characterized in that means are provided for attaching the free ends of the retaining means to the opposite side of the hold.

6. The vessel of claim 4, characterized in that means are provided for coupling the two adjacent ends of opposing retaining means, to form a unit.

7. The vessel of claim 1, characterized in that the rotation and retaining means are adapted to apply force to a generally rectangular float of timber presenting a width greater than the width of the hold, when the opening of the hold is located under the float of timber.

8. The vessel of claim 1, characterized in that the retaining means are adapted so that when the vessel is located beneath a load of timber floating on the surface of the water they can be directed obliquely upwards and fixed in this position to allow the timber to slide under its own weight down into the hold along said retaining means, when the vessel is raised.

9. The vessel of claim 1, characterized in that each rotation means is connected to two or more of the retaining means on one side ofthe hold so that said means at any moment of rotation form the same angle to the sides of the hull, and that each so connected unit is together by a means which presents a substantially flat surface facing the direction in which the retaining means exert the force against the load, wherein the load slides under its own weight along said surface when the retaining means are directed obliquely upwards.

10. The vessel of claim 1, characterized by means capable of being rotated about the shafts to steady in the cross direction of the vessel a deckload placed upon the load compacted in the hold by the retaining means, and wherein the load steadying means and the retaining means are connected to each other.

11. The vessel of claim 10, characterized in that the load steadying means and retaining means can be rotated by the rotation means independently of each other. 

